Journal of Sustainable Construction Materials and Technologies
Latest articles in this journal
Published: 8 February 2023
Journal of Sustainable Construction Materials and Technologies; https://doi.org/10.47481/jscmt.1214086
Rheoplastic lightweight concrete (RLC) is generally designed for pumping applications as fluid concrete free from segregation. Concrete is produced using polymeric admixtures to enhance concrete workability, strength, drying shrinkage and durability. This research was studied to investigate suitability of natural porous pumice aggregates in Turkey to obtain rheoplastic lightweight concrete with cement content in normal ranges. To produce and experience rheoplastic concrete mix design data, rheoplastic lightweight concrete mixes were tested with fine pumice aggregate (FPA) and coarse pumice aggregate (CPA) supplied from Nevşehir region of Turkey. For rheoplastic lightweight concrete with cement contents in the 250 to 400 kg/m3 range, the percentage of fine pumice aggregates required was in the 73.6-81.0% range with free water/cement ratios of between 0.53 and 0.68. Upper compressive strength limit was circa 30 N/mm2. From the research findings, it was determined that the rheoplastic concrete samples with pumice aggregate met the design requirement as slump value of 200 mm for fresh concrete predicted for fluid concrete forms. While technical properties of hardened concrete such as oven dry density, strength values, static elasticity modulus, thermal expansion coefficient and thermal conductivity value decrease with increasing aggregate/cement ratios, they increase with increasing cement dosage. In addition, presence of high amount of fine pumice in concrete composition results in lower drying shrinkage and wetting expansion with decreasing cement dosage. The technical findings showed that RLC might be produced by using superplasticizer and air-entraining admixtures and mixtures of different sizes of pumice aggregates.
Published: 7 February 2023
Journal of Sustainable Construction Materials and Technologies; https://doi.org/10.47481/jscmt.1207739
Cement-based materials are the most widely utilized construction materials in the world owing to their high compressive strength, however, need reinforcement to withstand direct or indirect tensile forces. In this study, the potential use of 3D-printed polymers as an alternative reinforcement in cement-based composites was evaluated. Polyethylene terephthalate glycol (PETG), Polyamide (PA), and Acrylonitrile butadiene styrene (ABS) based triangular and honeycomb-patterned 3D-printed reinforcements were incorporated into cement-based composites and their mechanical performances were compared under three-point flexural tests by considering both polymer and pattern type. Both triangular and honeycomb patterns were enhanced the flexural behavior. By considering all filaments, the honeycomb pattern was found more effective than the triangular pattern for increasing flexural strength, deflection capacity, and toughness up to 46.80%, 251.85%, and 77.66%, respectively. In the case of filament type, 3D-printed PA-type filament in a honeycomb pattern remained flexural strength, enhanced deflection capacity, and increased flexural toughness with pseudo-deflection hardening behavior. 3D-printed honeycomb patterned reinforcements produced by PA has the opportunity to be used in the manufacture of cement-based composites.
Published: 26 January 2023
Journal of Sustainable Construction Materials and Technologies; https://doi.org/10.47481/jscmt.1204757
Recycling end-of-life tires is a global problem that requires an urgent solution. Storing and preserving these tires is a challenge that delays facing potential problems instead of solving the problem. In this context, recycling waste tires without harming the environment and at low costs has been the focus of many researchers. For a few decades, the possibility of these tires to be granulated to the size of aggregate for concrete and then be replaced with natural aggregate has been a subject of research by scientists studying in this field. In this regard, this study aims to experimentally investigate the influence of waste rubber aggregate on some engineering properties of concrete, such as, ultrasonic pulse velocity-based quality assessment, abrasion resistance, and thermal conductivity characteristics as well as the mechanical performance, namely, compressive strength. Another significant side of the study was to establish a statistical relationship and correlation between the w/c ratio and substitution level of waste rubber aggregate and the experimental outputs. The experimental study indicated that the waste rubber aggregate decreased the compressive strength of the concretes whereas it improved the thermal conductivity characteristics and abrasion resistance of the concretes manufactured in this study. On the other hand, the statistical analysis revealed that the input parameters have meaningful effects on the engineering properties of the concretes, and there is a strong correlation between these properties.
Published: 31 December 2022
Journal of Sustainable Construction Materials and Technologies, Volume 7, pp 266-281; https://doi.org/10.47481/jscmt.1196292
Vermiculite exfoliation is based on the principle when water between the layers evaporate, and the crystal layers spread out pressured by the steam. As a result, elongated, curved particles are formed. The thermal properties of the final product formed are directly related to this exfoliation amount. In this experimental work, exfoliation characteristic of natural vermiculate is studied. A series of experimental analyzes were carried out to examine the expandability of natural vermiculite at different heating temperatures by the Na+ modification method. In addition, the expansion ratios of Na+-modified and unmodified vermiculite samples were analyzed comparatively. Each of the raw and Na+ modified vermiculite material groups prepared for the thermal expansion process was experimentally performed by recording the exfoliation states and times at six different heating temperature values of 350 oC, 450 oC, 530 oC, 620 oC, 710 oC and 840 oC, respectively, in a laboratory environment. In the second phase of the study, thermal properties of new generation composite mortars produced with exfoliated vermiculite aggregate were experimentally analyzed. Parameters such as thermal conductivity, heat storage capacity, specific heat and heat dissipation coefficient of mortar test samples prepared with exfoliated vermiculite aggregates are analyzed and discussed here. Test results showed that Na+-modified vermiculite samples expanded better than unmodified vermiculite samples for all expansion temperatures. When Na+-modified expanded vermiculite is evaluated in composite mortars, it also reduces the unit weight of the mortar as it expands more and the unit weight of itself decreases. Accordingly, the compressive strength of the mortar decreases relatively. However, it has been determined that the thermal comfort properties of mortars using Na-modified exfoliated vermiculite are better than the thermal comfort properties of composite mortars produced using unmodified exfoliated vermiculite.
Published: 31 December 2022
Journal of Sustainable Construction Materials and Technologies, Volume 7, pp 339-357; https://doi.org/10.47481/jscmt.1144427
In recent years, there has been a surge in interest in developing novel materials for sustainable building construction made from renewable resources. The use of natural fibers in concrete reinforcement, as opposed to agricultural waste, has significant environmental benefits in terms of reducing the environmental repercussions of the continuous dumping and landfilling of massive amounts of agricultural waste in overburdened landfill sites. Banana peel fiber (BPF) and orange peel fiber (OPF) are common agro-wastes with a long history of use in concrete as an additive or a cement substitute. However, their efficiency and performance in terms of reinforcement must be assessed. The characteristics, fresh and hardened state structural performance of BPF and OPF as composite materials in sustainable concrete manufacturing are reviewed in this study based on recent findings. For quality concrete reinforcing, it was discovered that OPF and BPF have good surface areas and low specific gravity. For quality concrete reinforcing, it was discovered that OPF and BPF have good surface areas and low specific gravity. BPF and OPF, on the other hand, have significant pozzolanic binding properties of up to 97.3 %. This allows them to act as binders and supplement the high strength yielding in concrete. Furthermore, the use of BPF in concrete enhanced workability, consistency, compressive and tensile strengths, and setting times by 21.1 %, 48.64 %, 46 % and 52.5 %, and 47.37 %, respectively, whereas the use of OPF raised concrete density by 5.34 %. This indicated that both BPF and OPF had a lot of potential for producing high-quality concrete. The use of BPF and OPF to reinforce concrete and composites against flexural deflection, heat transmission, and modulus of elasticity resulted in a significant increase in concrete strength in terms of cracking, deflection, creep, and shrinkage. The inclusion of orange and banana peels in concrete was found to significantly improve the structural qualities of the concrete; thus, they can be employed as supplementary materials in the manufacturing of concrete. Finally, this study identifies new approaches for achieving the much-anticipated biodegradability and sustainability of natural fiber-reinforced composites for usage in a variety of concrete reinforcing applications.
Published: 31 December 2022
Journal of Sustainable Construction Materials and Technologies, Volume 7, pp 291-301; https://doi.org/10.47481/jscmt.1165940
Functionally graded materials are composite materials used to build a variety of structures. These structures are used in ships industries, marine, automotive, high building structures, energy engineering applications, and many more. The porosity made in these materials may negatively affect some behavior aspects like stiffness, and strength, but it may provide superior performance in other fields like vibration reduction, thermal isolation, energy absorption, and others. In this paper, we will discuss the effect of porosity on the natural frequencies for functionally graded porous (FGP) sandwich beams. The mechanical properties of the FGP sandwich beams are changing with the porosity in the thickness direction. The free vibration of the beams is examined with the effect of porosity. The analysis is carried out for four different beam supporting types (hinged – hinged, fixed – fixed, fixed – free, fixed – hinged). Various porosity ratios are considered with a range from (0.1 – 0.9). Forty–four samples are analyzed for each type of core material distribution which is the symmetric material constitutive relationships (SMCR) and uniform core material. The results gained from the analysis show that the porosity constant has a significant effect on the natural frequencies of the FGP sandwich beams.
Published: 19 December 2022
Journal of Sustainable Construction Materials and Technologies; https://doi.org/10.47481/jscmt.1211086
Strengthening and rehabilitation have been widely implemented for many years to extend the service life of reinforced concrete structures. The paper begins with a comprehensive review of the fiber-reinforced polymers (FRP) utilization on strengthening particularly over the traditional materials formerly used in practice with respect to materials, manufacturing, operation, construction, and maintenance phases, as well as the engineering and environmental performance of such materials. Carbon and Glass FRP, the most frequently used strengthening materials, are particularly designated in the study and are employed to conduct an environmental performance evaluation using the previously published data in the literature. The paper then investigates the punching shear strength of flat slab-column connections strengthened with externally bonded FRP by means of a nominated database comprising 57 number of data points harvested from the recent literature. The database is used in the evaluation of the test data with TS 500 code equations and the recent modification of Chen and Li. The study enabled the key factors affecting the punching shear strength of such connections to be emphasized and highlighted the fact that the TS 500 code equations fall conservative in predicting the punching shear strength of slab-column connections strengthed with FRP. The study is novel as it provides a comprehensive review of the FRP as a strengthening material with regards to environmental sustainability and also provides an insight into the structural implications of this material by evaluating the current TS 500 code provisions and recent modifications.
Published: 15 December 2022
Journal of Sustainable Construction Materials and Technologies, Volume 7; https://doi.org/10.47481/jscmt.1209822
Phytoplankton and diatom microalgae species cause biofouling by adhering to the surfaces, especially in closed cultivation systems such as tubular photobioreactors. This biofilm formation blocks the sunlight; after harvesting, it is necessary to clean the reactor. This cleaning process causes loss not only for time and finance but also in terms of environmental pollution due to using toxic chemicals and excess water usage. This study aimed to investigate the reduction of the microorganism cell adhesion on the hybrid surface. To succeed in this, the composite surface of tetraethoxysilane (TEOS) and lactic acid (LA) was prepared by the sol-gel process. Then the hybrid surfaces were coated on glass slides by the dip coating method. The wettability performance of the TEOS-LA hybrid surface was investigated using contact angle measurement and light transmittance. The wettability result showed that the superhydrophilic surface having 54 mJ/m2 of surface free energy values was obtained. An increase in the lactic acid content of the composite films increased the surface free energy (SFE) values decreasing the water contact angle. A pencil hardness test characterized the mechanical strength of the surfaces, and it was determined that the hardness of the composite films was decreased by increasing the LA content of the composite films. Resultantly, it is found that the TEOS-LA superhydrophilic composite film reduces the adhesion of microalgae.
Published: 8 December 2022
Journal of Sustainable Construction Materials and Technologies, Volume 7; https://doi.org/10.47481/jscmt.1193891
Lightweight cellular hollow concrete (LCHC) block is a type of masonry unit that has excellent thermal and acoustic performance, fire resistance and high weathering resistance, and manufactured by precast technique. This work presents an experimental study, which investigates the effects of volumetric partial replacement of Portland cement by calcium sulfate anhydrite on precast properties, especially hardening time of the products, thermal insulation properties and mechanical properties of the blocks. LCHC block is produced by the mixing of Portland cement (PC), anhydrite III (ANH), expanded perlite (EP), pumice (PU) and calcite (CA) for building applications. The physical and mechanical properties of LCHC blocks having various replacement levels of ANH are studied. Experimental studies were carried out on both 10x10x10 cm3 cube specimens and 19x19x39 cm3 block specimens. In this research work, LCHC blocks with 16 different mixture batches were cast into a mould with vibro-compacting, de-moulded immediately and transferred to a storage area for curing up to 28 days in normal air condition. The unit weights and compressive strengths of the cube specimens decreased as the ANH replacement level increased, depending on the decrease in the cement ratio. However, it was observed that the compressive strength of the block specimens increased up to the volumetric replacement level of 1.86 %. As expected, the thermal conductivity values of the specimens decreased with the decrease in unit weight. The most notable change on the specimens occurred in the hardening time. The hardening process of the specimens can be completed up to 90 times faster than the control mixture. In addition, within the scope of the study, three formulations are presented in which the compressive strength and the elastic modulus of the wall sections made with LCHC blocks can be calculated, and thermal conductivity value of masonry block unit can be calculated.
Published: 22 November 2022
Journal of Sustainable Construction Materials and Technologies, Volume 7; https://doi.org/10.47481/jscmt.1197471
This paper presents an alternative environment-friendly thermal insulation material for the construction industry. We aimed to produce this building material with superior heat resistance properties and comparable strength to the concrete produced with Ordinary Portland Cement. The primary purpose of the experimental studies is to produce a basic geopolymeric plate and to add cellubor and polypropylene fibers to the geopolymeric mortar. In the next stage, fiber-reinforced plates were prepared, thermal experiments were carried out, and discussions and conclusions were formed according to the results and findings. This study initially produced different types of fiber-based metakaolin plates with high heat resistance. Then, the flame test examined the heat resistance of the composite plates formed by the mixture of fibers consisting of cellubor, polypropylene, and cellubor + polypropylene fiber mixtures into geopolymeric mortars. It was found that the metakaolin plates containing approximately 6% by weight of Cellubor in the structure, besides their serious resistance to flame, their heat retardancy properties gave 72% better results than Kalekim (cementitious ceramic tile adhesive) plates and 55% better results than non-fiber metakaolin plates.